GeeWhiz@cup.portal.com (Paul Terry Pryor) (03/01/89)
A stock Zenith 248 with 640K base memory and 2.5 meg extended memory was recently outfitted with 180 meg CDC Wren II drive and ESDI controller, and Everex 8000 populated with 6 meg of 100 ns DRAMS. As a precaution, IBM AT Advanced Diagnostics was ran, testing the memory. The tests indicated a refresh problem with Everex (within a few bytes past the Everex's starting address). The same Everex board was moved to Televideo, and passed AT Diagnostics with no problems whatever. A 4 meg Boco RAM board was substituted, and passed AT Diagnostics while sitting in Zenith. A few days later, Xenix panic'd with parity error. Any attempts to reboot the system resulted in a hundred 'memory parity errors' issued by ROM BIOS then the system locked up. The system had to be powered down then back up. The parity error disappeared. However, within a hour, the parity errors returned. This seems to indicate that there may be a serious problem with Zenith ram refresh timings. One of the companies we contacted regarding a 8 port serial board indicated that their board will not work in Zenith due to bus timing. I would appreciate any information you can offer to help me track the problem down and to locate the culprit(s). And any suggestions are welcomed ! And I would very much like to hear about anyone's experience with Zenith 248 series. Paul Pryor Integrated Microcomputer Systems, INC NASSIR ACIRS3+ Project Team Bailey's Crossroads, VA